The present invention relates to a transferring device of a cam type for use in automatic assembling or the like.
Generally, a line for automatically assembling various types of products (as shown in FIGS. 1 and 2), e.g., see part 9 in FIG. 2, requires a transferring device 7 (or 8) that can transfer parts 3 (or 4) on a conveyor 1 (or a part table 2) one by one, or few by few, to an assembling table 5 (or a conveyor 6) with respectively changing transferring distances. Further, the device is required to return to a constant initial position.
FIG. 1A illustrates an unequal pitch index machine which has already been developed for intermittently transferring pallets. In this machine, rotation of a motor 1A is transmitted through an unequal pitch index device 2A to a drive shaft 4A of a timing belt 3A. The belt 3A intermittently transfers jigs 5A on which many pallets 6A are located. During the transference, a locating pin 7A locates and positions the jigs 5A. Works are supplied to a position P by a picking and placing unit (hereinafter referred to as PPU) which picks-up the works on the pallet 6A and transfers them to the position P. This PPU comprises a transferring mechanism which reciprocates between the work supply position P and the pallets in rows along picking-out line 8A (a center line of PPU) shown in FIG. 2A.
As shown in FIG. 2A, an operation starts when the center of the pallets at the right end row aligns with the picking-out line 8A. The unequal pitch index machine intermittently drives the belt four times with pitches of x1. During each stoppage, PPU reciprocates different strokes l1, l2, l3 and l4 on the picking-out line 8A to transfer the works on each pallet 6A to the work supplying position P, and thus, the works in all pallets 6A on the jig 5A can be taken out. When the taking-out operation on the line 8A is completed in the pallets at the left end row on the jig 5A, the unequal pitch index machine 2A drives the timing belt 3A a length of s+.alpha., and a new pallet filled with the works is conveyed to the initial position and stopped there.
Transferring devices having driving mechanisms of the cam type are known which are suitable for use with automatic assembling devices of the types described above, especially in high speed operations, but they are not able to change the displacement in order to accommodate different transferring distances.
Accordingly, it is an object of the invention to provide such transferring device of the cam type that can transfer parts one by one, or few by few, and is able to change the transferring distance and can always return to an initial position.